2001 Challenger 2000 Throttle Set Up

[poinddexter]

So I just got the motor put in (its a 240hp efi) and the timing set as well as the TPS set. The engine idles nice 1000rpm) and will rev smoothly through the entire range of the throttle movement. The problem is it tops out at about 4200rpm. I went back and checked the tps and its still a perfect .299 volts at idle position. The problem I'm seeing is that the throttle doesn't seem to pull the linkage all the way forward. When I set up the tps I did it with the throttle cable disconnected and the cam being pulled all the way forward by a helper. I got the full throttle voltage to read ~7.4 so I figured everything was good. After putting the boat in and seeing that I could only get 4200rpm I went back and checked the tps and I'm seeing that the throttle will only pull the tps to about ~5.6 volts. I took the helm apart as I did read once that there are different cable mounts that give it different pull lengths. It was mounted on the center hole so I moved it to the outer hole (appeared to be longer throw) and put it back together. I now get ~6.0 volts and about 4500 rpm but I can still grab the throttle cam pull it ahead more. I've adjusted the cable as tight as I can see being able to without affecting the idle setting. Is there something that I am missing as far as adjusting something goes? All tps adjustments were done with the port side head sensor disconnected. This boat is new to me and I'm still trying to figure everything out. Thanks!

 

[poinddexter]

Just a quick update, it turned out to be the throttle link arm (that bent wire looking thing) i turned it out 3 turns and now have 7.5 volts at the TPS with WOT. Will be water testing as soon as my steering cable comes in. Its something to consider if your boat won't open up full since there is no mention of it, that i could find, in the manual.

 

[Dr Honda]

There's a big section on setting up the throttle, the links, and the cam in the Mercury manual.

But...

if you are only getting to 4500 rpm, (kind of a magic number) even with some of the playing... I would be suspect that 2 cyl's aren't firing. You could have a bad trigger.

 

[poinddexter]

I have spark on all 6 cylinders at least at idle. Throttle guardian is disconnected as well. I don't think the throttle was opening all the way before. I can water test it as soon as my steering cable comes in and let you know.

 

[philipmurphey]

I have the same boat, same year, with the same issue but was hitting 4900 RPM max. I also checked for spark on all 6 and all appear good. I looked into the throttle not opening fully due to seller telling me that he just put a new cable on it and I figured that he did not adjust properly. Turns out that the full throttle adjuster bolt that limits the how far it can pull was adjusted to far out and not allowing a full sweep of the butterflies. I turned it in a few turns and can no longer turn butterflies cam any more. I will water test and hope that was my issue as well.